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<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>
    <script>
        var a = 10
        var b = 5
        // 三目运算 条件 返回（？）为真 返回（：）为假
        var c = a > b ? a : b
        


        // 定义数组
        var a = ["html","js","jq","py"]
        document.write(a[0] + "<br/>")
        // 赋值
        a[4]="vue"
        document.write(a)
        // 获取长度
        document.write(a.length)
        // push 向数组添加一个元素
        a.push("c++")
        document.write("<br/>" +a)
    </script>
</body>
</html>